Mark shoeld



M. SHOELD. PRODUCTION UF FOTASSIUM CHUJRIDE. APPucmoN min Nov.11. m2o.

1 402 973 Patented Jan.10,1922.

w 11mm. mw la l vfutur-151DA sTATEs v T0 all whomfit may concern:

PATENT OFFICE.

, MARK sHoELn, or emesso, ILLiirors, Assrrron To Annone FERTILIZER wenns, or'

CHICAGO, ILLINoIs; A CORPORATION or NEW JERSEY.

Be it 'known that I, MARK 'Slicer'.n, a citizen of thev United VStz'1-tes'residin at Chicago, inthe county of Cookrand tate of Illinois, have invented certain' ne\v and u'sei'ul Improvements in the Production of 'Pot'ssium Chloride, of which the following 11s a specification.

My invention relatesVV to novel processes or methods capable of being Worked on e` commercial scale lfor jthe recovery of the potzish from leuciteo-r Wyoiningite, containmg e double ,silicate of aluminum und p'otassium, or similar minerals, its prime object being the removal or extraction of the potl ushflrom the mineral, hence renderinf,r it available, by substituting il, suitable base therefor, as by vthe employment of e solution of it relativelyT common und cheep salt und the use of appropriate pressure and suitable tem) Jervatnre.A i

One importent: feature oi the invention resides inthe continuity `oithe process whereby it can be economically practiced,

n further valuable characteristic being the desirable :find effective wet grinding of the mineral in the sultrs'olution, the ingredients of the resulting pulp being subsequently brought to the proper ratio or proportion es :i greater amount of the salt solution is required for the ,gfrindirtq` then cen Inter he employed to advantage during the digestion of the sludge under heat and pressure. f

Additional features of the invention pro! vide foi-'the use of a salt .solution not too concentrated und the'avoidunce of toov high n. steam pressure during the digestiomwhich, of course, tends to economy in the prnctice of the process. I

Another purpose of the invention is to employ the salt, or nt least :i part of it, iinctioned out oi' the strong)r liquor seperated trom the wuste sludge` the lutter being preferably washed` in the treatment of further material in the proportioning tank preliminarir to the digestion.

ln its preferred form, the invention comprises the crushingr of the leucite or other similar mineral to ztsuituble size und then grinding it wet with e common seit or sodium chloride solution, whereupon the sludn'e is thickened, the clear salt-solution passingv beck to the snit-solution storage tank, the thickened pulp Flowing;l to n stor- Y rnontrerron or PouAssIUM-onnonimi 'Specification of Letters Patent. 'Patented Jilin. 10, 1922'. Appncation'iiied Noveniber rz, 192e'. serial No. 424,574. i

ege ltank where itis subjected to vagitation to"prevent settling.' From such tenir the materiel goes to n p'roportioning tank ivliereV digesters it traverses in sequence, whereupon i the liquid flows through n, double pipe'heet exchanger to give 'up e portion of its heat to `the'irmjter'ml .passing to the digesters. In the digesters theldesired chemical. transformation takes place, that is to say, the sodium of the solution is substituted for the potassium in the mineral, the potassium now being'present es potassium chloride in the solution, the letter` also` containing n portion of sodium chloride by reason of the excess originally employed. By frectionel eve oretion or otherwise the solid sodium choride find' solid potassium chloride are' removed from the strongr liquor, the former being returned for further use in carrying on the process, the letter representing the desired product, which may be used as a. fertilizeror employed otherwise in the nrt. Y,

In order that those skilled in this irrt lmuy have a` full end complete understandv Referringto the dra-Wing, it will be per! ceived thatthe leucite or similar mineral is fed continuously to u gyrntory or other Suitable Crusher 21, by which it is reduced to one und onedmlf to two inch size, from which it pusses to u roll crusher 22 ol5 the customary form which further reduces it to five to ten mesh size, und From the lutter crusher it `roes directly to 'fi rotary bull-mill 2,3 of the usuel construction to which also u sodium chloride solution is fed through :i pipe 25 from a salt-solution storage or supplv tank 24, 'whereby economical vwel; grinding of the mineral to e fineness of :ipproximetely 100 mesh occures in the mill.

By means of suitable supplies of water 26 :uid sodium chloride 27, the storegetnnk 247mg' be maintained properly filled with the Salt-solution of proper strength or specific gravity.'

The discharge from the ball mill flows into an inclined, single-deck classifier 2R of the standard andwell-known D o'rr type which returns the coarse material to the ball-rnill -for further grinding` the pulp continuously overflowing into ev Dorr thickener 29 where it is dewetered to approximately 4.0 er cent. solids,

' he clear salt-solution from the upper part of the thickener, which may be equipped with an appropriate agitator, is returned by ply-compartment 24 from time to time, as

may be required to maintain ix strength of about 20 to 25 per cent sodium chloride, the latter being conveniently handled by u screen-basket 34 suspended in the solution.

More of the solution is needed for the wet grinding than is suitiible or economical for the subsequent treatment in the diges- 1in-rs, hcnt'e'the proper amount of solution is constantly fed to the bull-mill from the `supply-trink, the cleur snit-solutionbcing continuously removed from the pulp in the thiokener und returned to such tank, und then the material is proportioned in tank 32 by the steady addition of salt-solution from the supply to provide n sludge containing by weight approximately three parts of ground Ieucitc, one part of sodium-chloride, und four to five parts of Water.

A triplexpump 35 takes the material from the proportioning-tunk and passes it through one pipr of :i double-pipe heat-cxchzlnge 3G, by which it is preliniinarily heuted, into i1 group or system of three di gestore', Il?, 38 und 35) which it traverses in seriesl and wherein it is :Lgitatrd or stirred and subjected to heut and pressure by the introduction into the digesters through pipes` 4U of live steam of approximately 2U() pounds pressure perfsquere inch, whereby the temperature of the lnateriul undergoing treatment in the digesters is maintained in the. neighborhood of 200 degrees oentigrzide.

The speed of flow of the mziterinl is such thnt it remains in thc digesters ordinarily from thirty minutes to one hour, three-lliurterS of an hour being a fair average` ut the end of which period the interchange of the sodium of the solution and the potassium of the mineral vill have taken pliicethe solution asidefrom its suspended solids now containing both potassium chloride and sodium chloride, the latter by reason of its original excess in the/solution.

Upon leaving the last digester, the sludge passes through a conduit 4l, the companion pipe of the heat-exchanger whereit imparts or delivers a portion of its heat to the material entering the digesters throughthe other pipe, anda. connection 42 to four Dorr thickeners 43,44, and 4 6 act-ing as Wushers, wherein the insoluble material is completely and thoroughly washed by Water introduced through -u pipe 47 into the final washer or thickener 46 and which flows on the launders or troughs of the several washers in sequence countercurrent to the sludge. As is clearly illustrated, the liquid in each thickener or washer overflows int-o the next one just below it, the sludge removed from the bottom of each washer being carried up to the next one,where it encounters the overflow from the Washer above, before it is delivered into-sugli vintermediate washer. The washed sludge in which the potassium has been replaced by the sodium leaves the final thickener 46 ii'nd passes out as waste.

The strong solution from washer 43 is pumped continuonsly through a connection 48, :i olarifyingpress 49, preferably of the Kellyv type`v and [u connection 5() to a Stor :ige-chamber 5l, from which, the clear liquor is continuously drawn or introduced through u connection 52 into the fourth effeet portion 53 of u quadruple-effect evaporutor 53, 54, 55, 56 of, the ordinary construction, the liquor, as is indicated, traversing thefour portions or sections of such evaporator in series und continuously leaving the piirt 56 as a concentrated solution at boiling temperature.

'lbrough u suitable connection 57 the hot solution or strong liquor isjrun through u system of three, open evaporators 58, 59 und GU acting unitedly as u fractionation uppnrutus wherein the sodium chloride is precipitated out und scraped up iilong the slightly-inclined side-walls (in much the sume way as in a Dorr classifier) und delivered into the next Section, the solid sodium chloride being discharged from the part 58 und returned for use in the salt-solution storage-tunk 24. The solutionrfiows through the appliance countercurrcnt or in thc opposite directionV to the travel ofthe sodium chloride, being delivered from each section of the evaporator, through the connection 61 or 62 :is the case may be, into the next one part wily down its inclined u'ull so as not to interfere with the sult traveling upwardly on the top portion of Such wall.

Upon leaving the tinul evaporator the lOl LlO

(i ll strong potassium chloride liquor asses through a connection to a system o three cooler agitators 64, 65 and 661 which it traverses in series..

From the last of these coolers the 'mix` ture of crystallized potassium-chloride and mother-liquor is runthrough 'a connection 67 .to either' one of two centrifuges 6 8 and 69, the latter being usedl alternately to permit removal of the potassium chloride from the previously active vbut now idle centrif luge; The mother-liquor from these centrifugal separators is returned te the middle section or part 59 `ofthe fractionation evaporator through a connection 70, andthe dried or centrifuged potassium chloride is ready for shipment upon removal from the separator.

Suitable pumpsl are employed in the system at the pointsV needec, but no attempt has been made to illustrate them. 1

It is to be understood that the process isI continuous, the leucite being round Without interruption, the solidso ium chloride and potassium chloride being discharged continuously.

ln the performance'ot the processes above specified, about per cent to 90 er cent oi the potassiumv in the minera is re'- placed by the sodium. The invention, however, is not necessarily limited or confined to the exact Ydetails of the process set forth (suchrasthe percentages of -ingredients in the sludge, the inene'ss of grinding, the strength of the salt-solution, the pressure and temperature, etc.,) nor to the apparatus illustrated and described,but the specification of the process as presented is thc preferred manner of practicing it so far as I am now advised. 4

Experience has indicated that if less Water is used the percentage of conversion decreases, whereas it' more Water is employed there is no substantial increase in conversion. F or example, il three parts of water are used instead of four to five parts, the conversion drops to about 70`per cent.

It more sodium chloride is used there is practically no improvement in conversion, and it less salt is availed of the conversion is reduced materially.

rlhe specified pressure of 2U() pounds per square inch seems toloe the most expedient from :i commercial standpoint. Il the pressure is less, the chemical interchange or sulr stil ution correspondingly decreases, Whereas ii' the pressure is increased substantially, there will he a small increase in conversion but not suilicient to Warrant the maintenance or the higher pressure. For instance, if the pressure is raised to three to five hundred pounds we secure only one or two per cent llltYBlSQ ln COllVBTSlOl.

The time ot treatment of the material in the digesters is desirably trom thirty minutes Ato "one hourf Ifjsueh lperiod is reduced te under jfiteen minutes, there is aperceptible Adrop inv the chemical transposition, Whereas if the time `is increased, say to live hours, the increaseinconversion is only about one per cent. The time factor, of course, may be modified as occasion requires to produce the most satisfactory-results.

Those'skilled in thisart `will understand,

therefore, that the invention is not necessarily restricted to the precise and exact deltails of the processand apparatus set forth because these are' subject to more or less radical` vmodifications -Wlthout Vdeparture from thesubstance and essence of the invention as defined by theappended claims and withoutfsacricing any of its substantial benefits and advantages.

I claim:

' 1. A process for the production of potassium chloride' from leucite or the like, coin# and the sodium of the solution, and removin tlie potassium chloride from the liquor, su stantially as described.

2. A. lrecess for the production of potassium ehlloridel from leucite or the like, comprisingl Wet grinding of the mineral sodium chloride solution, subsequent proportioninsr of the ingredients of the sludge by the addition of sodium chloride, subjecting the sludge to sufficient heat and pressure for a period oi time to eii'ect the interchange ot the potassium of the mineraland the sodium oi the solution, separating the liquor trom the solid material, removing the sodium chloride from the liquor, and removing the potassium chloride from such liquor, substantially as described.

3. A process for the production ot' potassium chloride from leucite or the like, comprising Wet grinding of the mineral in a sodium chloride solution, thickening the resulting pulp by removing a. portion ot its salty solution, proportioning the iirf'rozlieuts ol such sludge by thev addition ot salt solution, subjecting the sludge to heatand pressure `tor a period of time sullirient to elecl; the interchange of the potassium ol' the mineral and the sodium of the solution. und removing the potassium chloride 4troni the liquor', substantially as described.

4. A process for the production ot potassium chloride from leucite or the like, cour prising Wet grinding of the mineral in a sodium chloride solution, thickening the rcsultingl pulp by removing a portion of its salt-solution, proportioning the ingredients ol" the sludge bythe addition of salt-solution.

lul O subjecting the sludge to suflicient heat and pressure for u period of time to effect the interchange of the otassium of the mineral and the sodium of t e solution, removing the sodium chloride from the liquor, :ind remov ing the potassium chloride from such liquor, substantially as described.

5, A process for the production ofv potassium lchloride from leucite or the like, comprising wet grindinfr fof the mineral in u sodium chloride solution fed to the grinding apparatus from u salt solution supply, thick` ening the resulting pulp by removing u portion of its salt solution and returning the latter to said supply, proportioning the ingredients of the sludge by the addition of salt solution from said supply, subjecting the sludge to sufficient lient und pressure for a period of time to etlect the interchange of the potassium of the mineral and the sodium of the` solution, and removing the potassium chloride from the liquor, substantially as described.

6. A process for the production of potassium chloride from leucite or the like, coinprising wetv grinding of the mineral in n sodium chloride solution fed to the grinding apparatus from a, A salt-Solution supply, thickening the resulting pulp by removing a portion of its salt-solution and returning the latter to said supply proportioning the ingredients of the sludge by the addition of salt-solution from said suppl subjecting the sludge to suflicient heat andy pressure for n period of time to eli'ect the interchange of the potassium of the mineral and the sodium of the solution, .removing the sodium chloride from the liquor, and removing the potassium chloride from such liquor, substantially as described.

7. A process for the production of potassium chloride from leueite or the like, comprising wet Grinding of the mineral in u sodium chlori e solution fed to the grinding apparatus from a snlt-solution supply, thickenlng the resultinv pulp by removing a portion of its salt-so ution and returning the latter to seid supply, proportioninff the ingredients of the sludge by the addition of salt-solution from said supply, subjecting the sludge to suilicient heut and pressure for n period of time to effect the interchange of the potassium of the mineral and the sodium of the solution, removing the sodium chloride from the liquor und returning it to said salt-solution supply, and removing the potassium chloride from such liquor, substantially es' described. l

8. Aprocess fortheproductionof potassium chloride from leucite or the like, comprising wet grindin of the mineral in a sodium chloride so ution fed to the grinding apparatus from a salt-solution supplyl thickening the resultin pulp by removing a portion of its salt-so ution und returning the latter to said supply, I )roportioningr the iugredients of the sludge by the addition of salt-solution from said supply', subjecting the sludge to sullicient heut und pressure for u period of time to effect the interchange of the potassium of the mineral and the sodium of the solution, washing the sludge, separuting the liquor from the washed sludge, removing the sodium chloride from suid liquor, and removin the potassium chloride from said liquor, su stantially as described.

9. A recess for the production of potos- Sium ch oride from leucite or the like, comprising wet grinding of the mineral in :i sodium chloride solution fed to the grinding apparatus from a. salt-solution supply, thickening the resulting pulp by removing a portion of its salt-solution und returning the latter to scid supply, proportioning the iiigredients of the sludge by the addition ol! salt-solution from said supply, subjecting the sludge to sulicient heat and pressure tor a period of time to effect the' interchange ol the potassium of the minera-l and the sodium of the solution, washing the sludge. sepuruting the liquor from the washed sludge, rcmoving the sodium chloride from said liquor and returning it to said salt-solution supply. and removing the potassium chloride from such liquor, substantially as described.

10. A process for the production oi potossiuin chloride from leucite or the like. couiprising wet grinding of the mineral in sodium chloride solution of about Q0 to Q5 per cent sodium chloride, thickening the result ing pulp by removing n. portion ot its sultsolution, proportioning the ingredients ot the sludge by the addition oisultsolution of substantially the same strength, subjecting the sludge to suilicient lient und pressure vFor a period of time to effect the interchange ol the potassium of the mineral und the sodium of the solution, removing the sodium chloride from the liquor, and removing the potassium chloride from such liquor, substantially as described.

ll. A process for the pioduction oi potassium chloride from leucite or the like` comprising continuous wet ,ojriudiugl of; the mineral in a. sodium chloride solution. subsequent continuous proportioniug ot the ingredients of the sludge by the addition of sodium chloride solution, continuous sul)- jection of the sludge to sufficient heut :unl pressure for a. period oi? time to offert: (ho interchange of the potassium oF the mineral sind the sodium of the solution` :unl continu: ous removal ot the potassium chloride from the liquor, substantially as described.

l2. A process for the production of potassium chloride from leucite or the like, comprising continuous wetv grinding of the mineral in a. sodium chloride solution, subsequent continuous proportioning ol" the ingredients of the sludge by the addition of sodium chloridel solution, continuous sub- '.Ijection ofthe sludge lto heat and pressure interchange-ofZthe; potassium of the .mineral a'nd'tliesodiuni' of the solution, continuous separation oftheliqu'or from thesolid me! j twink-continuous removal joli the sodium tassium chloride y, from `leu'cite.-orV the' like, V compri'slnglcon'linuous wet grinding of the i mineral in :1c-,sodium chloride solution,- continuous thickening of the resulting pulp by continuouslyv4 removing a portion of its salts'olu'- tion,jcontinuous proportioning of the ingredients lo1 the sludge by` the'addition of so- :diurn chloride solution, continuous subjection ofV the sludge to heatv and ressure for a period of time suilicient to: e ectl the Vinterchange of. the'potassium ofthe mineral and v scribed. l f i' "continuous proportioninp; c

thef'sodi'u'm chlorideof the solution, and 'continuous removal of the potassium chloride from the liquor, substantially as de- 14. 'A proces'sfor the productionof potassiumchloride fromleucite or the like, comprlsing continuousiyet grinding ofthe mineral 1n a sodium chloride solutlon, continuous tliickening of the resulting pulp bycontinu- Aously removing a portion of its salt solution,-

4 of theingredients 01" the .sludge'by-the at lition of salt solution, continuous'subjecting'of the sludge to sufficient heat andpressure for a period of time to electithe interchange of the potassiuni` of the niineraliand the sodium of thc solution, continuous separation of the liquor trom the sohd materiahcontinuous removal of: the sodium chloride Afrom the liquor, and

continuous removal of the potassium chloride from such liquor, substantially as described.

15.1 A process for .the production of potassium chloride rom'cleuclte or the like, comprisingcontinuous VWet grinding of the mineral in a sodium chloride solution continuously -ie'd to the Vgrinding .apparatus from a salt-solution supply, continuous thickening of the resulting pulp by removing a portion of .its salt solution and continuously returning the latter to said supply, continuous pro ortioning of the ingredients of the slu ge by theaddition of salt-solution from said supply, continuous subjecting of the sludge to sufficient heat and pressure for a.

period of time to effect the interchange of the Jotussium of the mineral and the sodium of tie solution, continuous removal of the sodium chloride from the liquor, and continuous removal of the potassium chloride from such liquor, substantially as described.

1G. A process for the production of potassium chloride from leucite or the like, comprising continuous wet grinding of the mineral a-sodium chloride solution of about twenty-to twenty-five per cent sodium chloride continuouslyfed-tothe grinding apparatus r'oinfa salt-solution supply, continuous thickeningof the resulting pulp by continuously removing a portion of ,its saltsolution and continuously. returning the lat addition of ,salt-solution, ronjisaid supply .producing-a sludgecontainingby Weight ap- .proximately three parts of leuci'te, about one tion, continuous washin of the sludge, continuous 'separation of tie liquor from the Washed sludgel continuous removal of the sodium .chloride from the liquor, and continuousv removal of the potassium chloride from. such liquor, substantially as described.

17;,A process for the production Vof potassiumchloride from leucite or the like, *comprising Wet grinding of the mineral in a sodium chloride solution fed to: the grinding apparatus from a saltfsolution supply. thickening the resulting pulp by removing a portion of its salt-solutionv and returning the latter to saidsupply,proportioning the ingredients of the sludge by the addition of salt solution from said supply,^efecting the interchange of the potassium of the mineral and the sodium of the solution by passing the sludo'e through a group of digesters in series su jected to steam pressure, heating the ingoing sludge by the sludge discharged from such digest-ers, washing the sludge by a current or water ioWing countercurrent to the travel of the sludge, separating the stron solution from the Washed sludge, clariin such solution", concentrating said solution y a uadruple effect evaporator, precipitating t e sodium` chloride out of the strong liquor discharoed from the quadruple effect evaporator' by an evaporation fractionation apparatus, returningthe precipitated sodium chloride to the salt-solution supply, cooling and agitating the remaining liquor, separating out the potassium chloride hy a centrifuge, and returning the motherliquorv to the evaporation fractionation apparatus, substantially as described.

18. A process for the production of potasslum chloride'from leucite or the like, comprising continuous wet grinding of the mineral in a sodium chloride solution fed continuously to the grinding apparatus from a salt-solution supply, continuous thickening of the resulting pulp by removing a portion of its salt-solution and continuously returning the latter to said supply, continuter to said' supply, v,continuous proportioning of lthe ingredients oi. thesludge 44by the about one part of sodium chloride, and ractically four to five parts of waterycon inu ous effecting of the interchange ofthe potassium of the mineral and the Sodium of the solution by continuously passing the slud e through a group of digesters in series Sujectedto a steam pressure of approximately two hundred Apouidsper square inch, continuous heating of the, ingoingsludge by the sludge discharged from such digesters, continuous Washing of the sludge by a current of water flowing countercurrent tothe travel of the sludge, continuous separation of the,

strong Solutionfrom the washed sludge, continuous clarifying of auch solution, continu-1 tation of the sodiumv chloride out of the Strongliquorfdischarged from the quadruple effect evaporator by an evaporationv frac tionaton apparatus, continuous :return of the precipitated sodium chloride to the saltsolution su' ply, continuous cooling 'and agitatingfof t e renliainingliquor,continuous separating out of the potassium chloride om the liquor; by a centrifuge; and` oontinuousV return ,of the mother liquor to the evaporation fractionation apparatus, substantially'as described. y

, MARK SHOELD. 

